A common challenge in designing systems that
require galvanic isolation is finding a cost-effective, space-efficient way
to isolate both power and data. While many commercially available solutions
exist for isolating data, isolating power often requires the unsatisfactory
choice between designing a custom, isolated supply or using costly discrete
isolated dc-to-dc converters. This challenge arises because traditional
isolators, such as optocouplers, can isolate data but cannot generate power,
whereas transformers can isolate power but are neither space nor
cost-effective for isolating most data channels.

Custom isolated supplies can be cost-effective
at high volumes, and they can deliver just the right level of performance
for the given application. However, they require both design expertise and
separate safety approvals, which add development time and cost. The second
option, discrete isolated dc-to-dc converters reduce development time and
consume less space; however, they are often more than twice the cost of
custom supplies, and they have limited isolation ratings.

Analog Devices iCoupler® products with
isoPower™ technology offer a new approach that greatly reduces size
and cost without compromising on data rate and isolation rating. It starts
with iCoupler digital isolators that employ chip scale
microtransformers in contrast to LEDs and photodiodes used in optocouplers.
Compared to optocouplers, iCoupler products consume less power,
achieve higher data rates and provide more precise timing; yet still provide
isolation ratings of up to 5 kV. With the introduction of iCoupler
technology more than five years ago, safe, reliable data transfer has been
provided by over 50 million channels of digital isolation.

The same transformers in these devices can be
used to make an isolated dc-to-dc converter, creating a total isolation
solution in one surface-mount package. Using Analog Devices’ isoPower
technology, a new family of devices integrates 50 mW of isolated power and
two 10 Mbps data channels with 2.5 kV isolation, providing a total solution
in one package.

Analog Devices’ ADuM524x products provide
galvanic isolation by transmitting data across an isolated transformer,
using integrated CMOS electronics for signal conditioning. The same chip
scale transformers are used to generate isolated power, but the CMOS
electronics drive the primary side, and then rectify and regulate the supply
on the isolated secondary side. The resulting internal dc-to-dc converter
supplies power to the isolated side of the ADuM524x and makes available up
to 10 mA of current at 5 V for use in a variety of applications.

The figure below compares SPI buses that are
isolated by optocouplers and a discrete dc-to-dc converter with Analog
Devices’ solution that uses one ADuM5240 dual-channel iCoupler with
isoPower and one ADuM1201 dual-channel iCoupler. The Analog
Devices’ solution reduces solution size and cost by more than 50%.

Analog Devices’ solution reduces size and cost by over
50%.

The ADuM524x iCoupler products with
isoPower technology, available in 8-lead SOIC packages and priced at
$2.95 per unit in 1k quantity, provide a simple, low cost, space-saving
isolation solution. In addition, Analog Devices offers a wide range of 2.5
kV standard isolators, and the ADuM240x family of 5 kV quad-channel
isolators, plus a range of application focused devices, for example, the
ADuM1230 isolated gate driver. For datasheets, free samples, and more
information, visit www.analog.com/iCoupler-tech.